Diastat for thermostat

Abstract

A diastat for a thermostat, relating to the field of temperature controller, comprising a membrane 2 and a cup-shaped element 3, wherein a filling cavity 5 filled with a medium is formed between the center of the membrane 2 and the cup-shaped element 3; both of the membrane and the cup-shaped element have flat edges, and periphery edges of the membrane and the cup-shaped element are connected and sealed to ensure the airtightness of the filling cavity; wherein the cup-shaped element 3 has a reinforcing portion 301 corresponding to the filling cavity for improving structural strength, wherein the membrane is a flat sheet, and a volume change in the medium may cause the membrane 2 to displace relative to the cup-shaped element 3.

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of temperature controller, and in particular to a diastat for a thermostat.BACKGROUND

[0002] An on-off module of a liquid expansion thermostat is commonly used in temperature control instrument in temperature control situations such as the household appliance industry, electric heating equipment, and refrigeration industry. The working principle of the on-off module of the liquid expansion thermostat is based on the principle of thermal expansion and contraction, by filling a medium into a sealed cavity in a diastat formed by a membrane capsule, a capillary tube, and temperature-sensing cylinder, and making use of the characteristics that the medium expands when heated and contracts when cooled. When the temperature-sensing cylinder senses temperature changes in the external environment, the volume of the filled medium changes, by expansion or by boiling, causing the membrane of the membrane capsule to displace, which in turn actuates the switch contacts to be opened and closed. When the temperature rises, the switch contacts are opened, and when the temperature drops, the switch contacts are closed, thus achieving temperature control.

[0003] Fig. 1 illustrates a specific structure of the membrane capsule in a traditional diastat, including a dome-shaped disc 1, a stamped cup with offset flange 8, and a capillary tube 4. A membrane is formed in the middle of the dome-shaped disc 8, the stamped cup with offset flange 8 is made by stamping, and the capillary tube 4 is welded onto the stamped cup with offset flange 8. The stamped cup with offset flange 8 has the same shape as the commercially available 3 / 4-inch disc thermostat. During manufacturing, the dome-shaped disc 1 is embedded into the stamped cup with offset flange 8, and the weld between the dome-shaped disc 1 and the stamped cup with offset flange 8 was made by a circular weld between two concentric cylinders in contact, produced by a seam welding machine. However, the drawbacks of this structure are that the processing is complex, and as seen in Fig. 1, both of the dome-shaped disc 1 and the stamped cup with offset flange 8 have edges that are bent to form a hat-shaped structure, requiring a relatively large quantity of material used in manufacturing, which not only increases costs but also results in a bulky structure, hindering the spread and development of this structure.

[0004] Thus, it is necessary to provide a new diastat for a thermostat to overcome the above-mentioned deficiencies.SUMMARY

[0005] In order to overcome the deficiencies in the prior art, provided herein is a diastat for a thermostat, which is simple in structure, easy to process, advantageous in material saving and cost saving.

[0006] It is an object of the present invention to solve the technical problems above-mentioned by following technical solutions: A diastat for a thermostat, comprising a membrane and a cup-shaped element, wherein a filling cavity filled with a medium is formed between the center of the membrane and the cup-shaped element; both of the membrane and the cup-shaped element have flat edges, and periphery edges of the membrane and the cup-shaped element are connected and sealed to ensure the airtightness of the filling cavity; wherein the cup-shaped element has a reinforcing portion corresponding to the filling cavity for improving structural strength, wherein the membrane is a flat sheet, and a volume change in the medium may cause the membrane to displace relative to the cup-shaped element.

[0007] Further, the reinforcing portion is a bending portion.

[0008] Further, both of the membrane and the cup-shaped element are formed in an outwardly convex shape.

[0009] Further, both of the membrane and the cup-shaped element have an overlapping portion stamped near their edges for mating with each other.

[0010] Further, a welding edge is provided at a junction of the periphery edges of the membrane and the cup-shaped element.

[0011] Further, the cup-shaped element is recessed in a middle to form a mounting portion for embedding and installing the capillary tube.

[0012] Further, projection areas of the cup-shaped element and the membrane overlap completely with each other when viewed along the longitudinal direction of the capillary tube.

[0013] Further, one end of the capillary tube is connected to the cup-shaped element, and a middle of the capillary tube forms a coiled section, while the other end of the capillary tube forms a sealed portion by press stroke.

[0014] Further, the other end of the capillary tube has a welded portion.

[0015] Compared with the prior art, the present invention has the following beneficial effects: both of the membrane and the cup-shaped element have flat edges, and the filling cavity is formed into a sealed space by welding, which is convenient for processing and also advantageous in material-saving and cost-saving; a welding edge is provided at the junction of the periphery edges of the membrane and the cup-shaped element, and the welding edge can be welded by laser or micro plasma, thereby improving the airtightness performance of the filling cavity and reducing the risk of leakage.BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings tend to provide a further understanding of the present invention, and to explain the present invention in conjunction with the embodiments, but do not tend to limit the present invention, wherein: FIG. 1 is a schematic view of the specific structure of a membrane capsule in a traditional diastat; FIG. 2 is a schematic view of the structure of a diastat according to an embodiment of the present invention; FIG. 3 is an enlarged view of the junction of the membrane and the cup-shaped element according to an embodiment of the present invention; FIG. 4 is an enlarged view of the junction of the membrane and the cup-shaped element with a welding edge according to an embodiment of the present invention; FIG. 5 is a schematic view of the structure of the membrane, the cup-shaped element, and the capillary tube according to an embodiment of the present invention. Reference Signs List:

[0017] 1. disc; 2. membrane; 3. cup-shaped element; 301. bending portion; 302. mounting portion; 4. capillary tube; 401. coiled section; 402. sealed portion; 403. welded portion; 5. filling cavity; 6. overlapping portion; 7. welding edge; 8. stamped cup with offset flange. DETAILED DESCRIPTION OF EMBODIMENTS

[0018] A further detailed description of embodiments of the present invention will be presented below accompanying with the drawings. It will be appreciated that the preferred embodiments described are only for illustration and explanation of the present invention and do not tend to limit the present invention.

[0019] Fig. 1 illustrates a specific structure of the membrane capsule in a traditional diastat, which has been described in the background, and is not be repeated herein.

[0020] As shown in Fig. 2 to Fig. 5, the present invention seeks to protect a diastat for a thermostat, comprising a membrane 2 and a cup-shaped element 3, wherein the membrane 2 is displaced such that the switch contacts of the thermostat are opened and closed; the membrane 2 and the cup-shaped element 3 is distinguishing from the traditional structure in that, both of the membrane 2 and the cup-shaped element 3 have flat edges rather than the hat-shaped structure as shown in Fig. 1, which is advantageous in material-saving and cost-saving.

[0021] Specifically, a filling cavity 5 filled with a medium is formed between the center of the membrane 2 and the cup-shaped element 3; as shown in Fig. 2, both of the membrane 2 and the cup-shaped element 3 are formed in an outwardly convex shape, i.e., the membrane 2 protrudes towards an opposite direction of the cup-shaped element 3, whereas the cup-shaped element 3 protrudes towards an opposite direction of the membrane 2. This structure increases the volume of the filling cavity 5, such that the displacement of the membrane 2 is more significant when it displaces, which is beneficial to send an actuation signal to the switch contacts of the thermostat.

[0022] In this embodiment, periphery edges of the membrane 2 and the cup-shaped element 3 are connected and sealed to ensure the airtightness of the filling cavity 5, such that the membrane 2 is beneficial to displace due to the volume changes in the heated medium. The cup-shaped element 3 has a reinforcing portion corresponding to the filling cavity 5 for improving structural strength, that is, the cup-shaped element 3 has a relatively high hardness, such that the volume changes in the medium may fail to cause any displacement of the cup-shaped element 3. In contrast, the membrane 2 is a flat sheet, such that the volume changes in the medium may cause the membrane 2 to displace relative to the cup-shaped element 3.

[0023] In this embodiment, the reinforcing portion is a bending portion 301, which helps to strengthen the structure of the cup-shaped element 3.

[0024] In this embodiment, after the cup-shaped element 3 and the membrane 2 are combined and can be welded together at their junction by using flat welding equipment. In order to make the cup-shaped element 3 and the membrane 2 combing more compactly, both of the membrane 2 and the cup-shaped element 3 have an overlapping portion 6 stamped near their edges for mating with each other, which may enhance the tightness of their combination and prevent them from sliding relative to each other after being combined.

[0025] As a further optimized process, a welding edge 7 is provided at a junction of the periphery edges of the membrane 2 and the cup-shaped element 3. The welding edge 7 can be welded by laser or micro-plasma welding, so as to enhance the sealing performance of the filling cavity 5 and reduce the risk of leakage.

[0026] The cup-shaped element 3 is recessed in the middle to form a mounting portion 302 for embedding and installing the capillary tube 4, such that the capillary tube 4 can be fixed into the mounting portion 302 by welding.

[0027] As shown in Fig. 5, one end of the capillary tube 4 is connected to the cup-shaped element 3, and the middle of the capillary tube 4 forms a coiled section 401, while the other end of the capillary tube 4 forms a sealed portion 402 by press stroke and forms a welded portion 403 by welding, wherein the sealed portion 402 and the welded portion 403 are configured for improving the airtightness of the capillary tube 4. The capillary tube 4 can be coiled as shown in Fig. 5, but it can also be coiled with a larger diameter, be straight, or be curved in one or more portions, in other words, there is no limit to the shape of the capillary tube 4, and all shapes fall within the protection scope of the present invention.

[0028] The projection areas of the cup-shaped element 3 and the membrane 2 overlap completely with each other when viewed along the longitudinal direction of the capillary tube 4, indicating that the cup-shaped element 3 and the membrane 2 have the same size for matching perfectly with each other, so as to form a compact structure which is advantageous in material-saving.

[0029] Lastly, it should be noted that the above is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Although the present invention has been described in details with reference to the embodiments, those skilled in the art can modify the technical solutions herein or make equivalent substitutions of some of the technical features therein, but any modifications, equivalent substitutions, improvements, etc., which are made in accordance with the spirit and principles of the present invention fall within the protection scope of the present invention.

Claims

1. A diastat for a thermostat, comprising a membrane and a cup-shaped element, wherein a filling cavity filled with a medium is formed between a center of the membrane and the cup-shaped element; characterized in that, both of the membrane and the cup-shaped element have a flat edge, and periphery edges of the membrane and the cup-shaped element are connected and sealed to ensure the airtightness of the filling cavity; wherein the cup-shaped element has a reinforcing portion corresponding to the filling cavity for improving structural strength, wherein the membrane is a flat sheet, and a volume change in the medium causes the membrane to displace relative to the cup-shaped element.

2. The diastat for a thermostat according to claim 1, characterized in that, the reinforcing portion is a bending portion.

3. The diastat for a thermostat according to claim 1, characterized in that, both of the membrane and the cup-shaped element are formed in an outwardly convex shape.

4. The diastat for a thermostat according to claim 1, characterized in that, both of the membrane and the cup-shaped element have an overlapping portion stamped near the edges of the membrane and the cup-shaped element for mating with each other.

5. The diastat for a thermostat according to anyone of claims 1 to 4, characterized in that, a welding edge is provided at a junction of the periphery edges of the membrane and the cup-shaped element.

6. The diastat for a thermostat according to claim 5, characterized in that, the cup-shaped element is recessed in a middle to form a mounting portion for embedding and installing the capillary tube.

7. The diastat for a thermostat according to claim 6, characterized in that, projection areas of the cup-shaped element and the membrane overlap completely with each other when viewed along the longitudinal direction of the capillary tube.

8. The diastat for a thermostat according to claim 6, characterized in that, one end of the capillary tube is connected to the cup-shaped element, and a middle of the capillary tube forms a coiled section, while the other end of the capillary tube forms a sealed portion by press stroke.

9. The diastat for a thermostat according to claim 8, characterized in that, the other end of the capillary tube has a welded portion.

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